I disagree with Alex Rosenberg and Tyler Curtain’s characterization of science in general and economics in particular. They claim that a scientific discipline is to be judged primarily on its predictions, and on that basis, they suggest, economics doesn’t qualify as a science.

Prediction is certainly a valuable goal in science, but not the only one. Explanation is also important, and there are plenty of sciences that do a lot of explaining and not much predicting. Seismology, for example, has taught us why earthquakes occur, but doesn’t tell Californians when they’ll be hit by “the big one.”

And through meteorology we know essentially how hurricanes form, even though we can’t say where the next storm will arise.

In the same way, economic theory provides a good understanding of how financial derivatives are priced (notwithstanding Mr. Rosenberg and Mr. Curtain’s snarky reference to the Black-Scholes model). But that doesn’t mean that we know whether the derivatives market will crash this year.

Perhaps one day earthquakes, hurricanes and financial crashes will all be predictable. But we don’t have to wait until then for seismology, meteorology and economics to become sciences; they already are.

The writer, a university professor at Harvard, is a 2007 Nobel laureate in economics.

Readers React

It seems that every discipline, not just economics, wants to be a science. We have social science, political science, and even religion wants to be a science — witness Christian Science and creation science. And all the science wannabes can “explain” many things.

But none of them, including economics, can predict anything with significantly better than random success. Professor Maskin tries to compare economics with meteorology, but if economists could predict the next day’s stock market move with anywhere near the accuracy that meteorologists can predict the next day’s weather, they would be billionaires in short order.

Economics is great at “explaining” the past, but has nothing even remotely reliable to say about the future. So I’m afraid that the honest assessment is that none of the social “sciences,” including economics, really deserve the name as yet.

DAVID GOLDSCHMIDTOakland, Calif., Aug. 29, 2013

Seriously? Alex Rosenberg and Tyler Curtain claim that economics doesn’t qualify as a science because a science should be “judged primarily on its predictions.”

In the past eight years, several economists have used standard economic models to correctly diagnose the housing bubble, as well as predict the crash of 2008, the subsequent Lesser Depression and the stalled recovery because of inadequate stimulus. These are the models taught in Macroeconomics 101 and 102, not obscure or esoteric theories.

Other economists’ and politicians’ willful ignorance of these models, to disastrous results, does not mean that economics is not a science. It means that, as argued in a recent Op-Ed essay by Adam Frank, we live in the “age of denial,” during which it is acceptable to prioritize personal prejudices over scientific fact, regardless of the consequences.

Someday we’ll look back on this era as the period of idiocy that it is.

JONATHAN CAREYSan Francisco, Aug. 29, 2013

Mr. Maskin’s distinction between prediction and explanation as different but equally valuable goals of science is a false one — the two are inextricably linked. The ability to predict is both what makes our explanations useful, and what confirms that our explanations are correct.

Mr. Maskin’s choice of meteorology as example is a good one. It’s true that in the long run “we can’t say where the next storm will arise,” but we are now very good at forecasting the short-term futures of tropical storms, so good that we can predict landfalls within miles and within hours, and give populations ample time to protect themselves (if people would only listen).

If only economics could make such a claim! If only we could see a market crash developing in the mid-Atlantic and accurately predict that it would likely become a Category 4 hurricane and strike the Carolina coast within a few days!

And more important, if only we could make such a prediction about market behavior without the prediction’s entirely changing the behavior of the markets! That’s the other critical difference between economics and meteorology, or physics, or any of the disciplines we properly call scientific.

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Lilli Carré

Economies are entirely man-made — their behavior is an aggregate of human behavior, not the product of deterministic mathematical principles. Economics looks like math, but that look is a misrepresentation, the most destructive expression of which is our unjustifiable reverence for market forces.

DAVID BERMANNew York, Aug. 29, 2013

Mr. Maskin argues that economics is a science like seismology in that it primarily provides explanations rather than predictions. But seismology does make predictions. For example, it would be substantial evidence against current seismological theories if most earthquakes in the next five years were not in the Pacific Ring of Fire.

But the Revere Award was given in 2010 to economists who did just that. First prize went to Steve Keen, who arrived at his predictions by modeling the economy as a chaotic system — precisely the way meteorologists are able to model (though not to predict) phenomena like hurricanes.

His view is that mainstream neoclassical economics fails to appreciate the chaotic dynamics of the modern debt-driven economy; it can neither predict nor explain financial instability. This debate so far seems to be focused on neoclassical economics, but the most mainstream part of a discipline is not guaranteed to be the most scientific.

ALEX DOUGLASLondon, Aug. 29, 2013

The writer is a research fellow in philosophy at King’s College, London, and the Institute of Philosophy.

Mr. Maskin seems to consider prediction and explanation — those two pillars of scientific practice — as entirely distinct. But explanations in physics and biology, the two most advanced sciences, are tested by submitting them to the crucible of predictive success. Explanation and prediction are simply not separate goals.

Mr. Maskin’s comparison of economics with nonlinear sciences like seismology and meteorology, which do not yield long-term predictions, is to no avail. While recent economic models use nonlinear equations, they are controversial and it is unclear what explanation even means in these sciences.

More important, few, if any, public policies are based on meteorology and seismology, while economics is the basis of significant, life-changing policies. Those policies assume that economics is a predictive science, that its explanations have survived empirical tests.

Do we really want economics to be regarded as a science in the same way that meteorology is a science? The victims of unpredictable earthquakes and storms may not think so.

JOHN DOUARDMontclair, N.J., Aug. 29, 2013

The Writer Responds

Messrs. Berman, Ruhmkorff and Goldschmidt all point out that even though seismology or meteorology can’t predict particular earthquakes or storms, they still make useful predictions of a more limited sort. These writers, as well as Mr. Douard, seem to think that the same isn’t true of economics.

But economic theory makes significant, if circumscribed, predictions, too. For instance, a sequence of celebrated journal articles in the 1980s and 1990s warned of the financial meltdown that could befall us if many banks were to make highly leveraged loans at the same time (loans in which most of the money comes from other banks), a premise that became reality in the time before the financial crisis of 2008.

(To be clear, these papers didn’t say there’d be a catastrophe for sure or exactly when it would occur, only that it was a serious possibility.)

If financial regulators had heeded this work and had placed reasonable limits on leverage, recent economic history would likely have been quite different.